{"id":1544,"date":"2022-09-12T08:36:20","date_gmt":"2022-09-12T00:36:20","guid":{"rendered":"https:\/\/zhuxinyong.com\/?p=1544"},"modified":"2022-09-12T08:51:12","modified_gmt":"2022-09-12T00:51:12","slug":"typescript-union-types","status":"publish","type":"post","link":"https:\/\/zhuxinyong.com\/?p=1544","title":{"rendered":"TypeScript &#8211; Union Types"},"content":{"rendered":"<p><img decoding=\"async\" src=\"https:\/\/zhuxinyong.com\/wp-content\/uploads\/2022\/09\/unions-type.png\" alt=\"unions-type\" \/><\/p>\n<p>Union Types \u79f0\u4e3a\u8054\u5408\u7c7b\u578b\uff0c\u5c31\u662f\u628a\u5b58\u5728\u7684\u7c7b\u578b\u8fdb\u884c\u7ec4\u5408\u6210\u4e3a\u4e00\u4e2a\u65b0\u7684\u7c7b\u578b\u3002\u6bd4\u5982\u6211\u4eec\u5b9a\u4e49\u4e00\u4e2a\u51fd\u6570\uff1a\u53ef\u4ee5\u63a5\u6536\u5b57\u7b26\u4e32\u6216\u6570\u5b57\u3002<\/p>\n<pre class=\"line-numbers\"><code class=\"language-plain_text\">function print(id:string | number){\n    console.log(id)\n}\n<\/code><\/pre>\n<p>\u5f53\u4f60\u8981\u5bf9\u53c2\u6570\u505a\u4e00\u4e9b\u64cd\u4f5c\u65f6\uff0cTypeScript \u53ea\u5141\u8bb8\u8054\u5408\u7684\u6240\u6709\u7c7b\u578b\u90fd\u6709\u7684\u65b9\u6cd5\u3002<\/p>\n<pre class=\"line-numbers\"><code class=\"language-plain_text\">function print(id:string | number){\n    console.log(id.toUpperCase())\n}\n<\/code><\/pre>\n<p>\u8fd9\u6837\u5c31\u4f1a\u62a5\u9519\uff0c\u56e0\u4e3a <code>number<\/code> \u6ca1\u6709 <code>toUpperCase<\/code> \u65b9\u6cd5\u3002\u89e3\u51b3\u65b9\u6cd5\u662f\uff1a\u4f7f\u7c7b\u578b\u66f4\u52a0\u7cbe\u51c6\u3002<\/p>\n<pre class=\"line-numbers\"><code class=\"language-plain_text\">function print(id:string | number){\n    if(typeof id === 'string'){\n        console.log(id.toUpperCase())\n    }else{\n        console.log(id)\n    }\n}\n<\/code><\/pre>\n<p>\u8fd8\u6709\u4e00\u79cd\u60c5\u51b5\uff0c\u8054\u5408\u7684\u7c7b\u578b\u6709\u76f8\u540c\u7684\u65b9\u6cd5\uff1a<\/p>\n<pre class=\"line-numbers\"><code class=\"language-plain_text\">function print(id:number[] | string){\n    console.log(id.slice(0,3))\n}\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>Union Types \u79f0\u4e3a\u8054\u5408\u7c7b\u578b\uff0c\u5c31\u662f\u628a\u5b58\u5728\u7684\u7c7b\u578b\u8fdb\u884c\u7ec4\u5408\u6210\u4e3a\u4e00\u4e2a\u65b0\u7684\u7c7b\u578b\u3002\u6bd4\u5982\u6211\u4eec\u5b9a\u4e49\u4e00\u4e2a\u51fd\u6570&#46;&#46;&#46;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2,20,3],"tags":[33,220],"class_list":["post-1544","post","type-post","status-publish","format-standard","hentry","category-all","category-frontend","category-tech","tag-typescript","tag-union-type"],"_links":{"self":[{"href":"https:\/\/zhuxinyong.com\/index.php?rest_route=\/wp\/v2\/posts\/1544","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/zhuxinyong.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/zhuxinyong.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/zhuxinyong.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/zhuxinyong.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1544"}],"version-history":[{"count":1,"href":"https:\/\/zhuxinyong.com\/index.php?rest_route=\/wp\/v2\/posts\/1544\/revisions"}],"predecessor-version":[{"id":1545,"href":"https:\/\/zhuxinyong.com\/index.php?rest_route=\/wp\/v2\/posts\/1544\/revisions\/1545"}],"wp:attachment":[{"href":"https:\/\/zhuxinyong.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1544"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/zhuxinyong.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1544"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/zhuxinyong.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1544"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}